3rd L Flashcards
explain the lesion of , Ant horn , post horn , lateral column , post column , lateral column in the in the cervical pare
1-Ant horn syndrome: Segmental paralysis(peripheral paralysis and atrophy of muscles innervated by the motor neurons of the corresponding segmented side as that of the lesion.
2-post horn : A longitudinal tear of the posterior horn of the medial meniscus is common in older people as degeneration may be present in the meniscal tissue. With this type of tear, the meniscus has been sliced in the middle - as if it were a bagel bun cut into to pieces
3-lateral column : ipsilateral paralysis (inability to move), paresis (decreased motor strength), and hypertonia (increased tone) for muscles innervated caudal to the level of injury
4-post column :Damage to the dorsal columns (fasciculus gracilis and cuneatus), bilaterally, causes the absence of light touch, vibration, and position sense, bilaterally, from the neck down (below the lesion level)
5- lateral column in the in the cervical pare :Brown-Séquard syndrome is a neurologic syndrome resulting from hemisection of the spinal cord. It manifests with weakness or paralysis and proprioceptive deficits on the side of the body ipsilateral to the lesion and loss of pain and temperature sensation on the contralateral side.
explain the lesion of spinal cord at the levels of , Cervical , thoracic , lumber
1-cervical :
- from c1-c4 : spastic , qudrapelagia , loss of all sensation below the level of lesion
-from c5-c8 : peripheral pepralagia of upper limbs , central papralagia of lower limbs , loss of all sensation , pelvic organ disorder , bernard horner syndrom
————-
2-Thoracis : T1-T12
lower spastic paraplegia , loss of all sensation below the lvl , pelvic organ disorder , vegetative trophic disorder in the lower half of the trunk and lower limbs limbs
———
3- lumber : L1 -s1
lower flacid , lower paraanthsia , pelvic organ disorder
explain the CSF , DF , formation , function , diseases
-DF :Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord
-Formation :CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the brain, and absorbed in the arachnoid granulations
-Function :
1-Protection
2-Prevention of brain ischemia
3-Regulation: CSF allows for the homeostatic regulation of the distribution of substances between cells of the brain
——–
-diseases :
1- meningitis bacterial and fungal
2-viral asceptoc mingitis
3- TB minigitis
4-subarchnoid hemorrhage
5- gulilian barre syndrome
anatomy of the cerebellum , overview , external feature
-Controls many aspects of coordination of movement, maintenance of body equilibrium, and movement initiation and planning. Exerts its control over the ipsilateral side of the body. Information is exchanged with the cerebellum via the cerebellar peduncles
-External Anatomy
Covers most of the posterior surface of the brain stem, forms the “roof” of fourth ventricle.
■ Posterolateral fissure: Flocculonodular lobe from posterior lobe.
■ Primary fissure: posterior lobe from anterior lobe.
■ Anterior and posterior lobes are divided into 3 longitudinal zones:
■ Vermis: Most medial zone.
■ Paravermis: Lies between vermis and hemispheres.
■ Cerebellar hemisphere: Large lateral portions.
■ Other structures: Flocculus, tonsils, nodulus, uvula, horizontal fissure.
■ There are 10 principal lobules
-Functional Anatomy : they are 3 :
1-Vestibulocerebellum: Located in flocculonodular lobe.
■ Input: Vestibular nuclei.
■ Output: Vestibular nuclei.
■ Function: Balance and eye movements, bidirectional communication helps to coordinate eye movements and body equilbrium.
2-pinocerebellum: Located in vermis and paravermis of anterior and posterior lobes.
■ Input: Vermis: vestibular nuclei and proprioceptive and sensory inputs from the head and neck. Paravermis: spinal cord (info on limb position from ascending spinocerebellar tracts).
■ Function: Coordinate motor control during motor execution.
Vermis: coordinates medial (axial) systems.
Paravermis: controls activity of lateral motor system (limb movement during ongoing motor activity).
3-Cerebrocerebellum: Located in large lateral zone cerebellar hemispheres.
■ Input: Contralateral, pontine nuclei.
■ Output: Motor and premotor cortical areas after stopping in VL thalamus.
■ Function: Involved in motor planning and initiation of movement.
–Microanatomy
-Cerebellar cortex consists of 3 layers:
-Outer molecular layer, Purkinje cell layer, and granular layer
■ Deep cerebellar nuclei (medial to lateral): Fastigial, globose, embolliform, dentate
■ Vestibulocerebellum (flocculonodular lobe) doesn’t project to a deep nucleus; rather, Purkinje cells send axons directly to vestibular nuclei.
explain the cerebellum afferent pathways
-Afferent tracts arise from three main sources: the cerebral cortex, the spinal cord, and the vestibular nerve. Afferent tracts are excitatory and travel to the cerebellum via mossy fibers and climbing fibers. Afferent tracts travel mainly through the inferior and middle cerebellar peduncles
-they are 5 pathways :
1-Olivocerebellar: Fibers arise from the olivary nucleus and decussate to reach the fibers of the opposite Raphe nucleus. From here they pass onwards as internal arcuate fibers, through the inferior peduncle, and to the opposite cerebellar hemisphere
2-Vestibulocerebellar: This is a pathway that joins the pontine tegmentum to the cerebellar cortex.
3-Reticulocerebellar: These fibers originate at various levels of the reticular formation and mainly terminate in the vermis (which lies in the midline).
4-Corticopontocerebellar tract: This connects the premotor areas to the contralateral cerebellar hemisphere via the pontocerebellar tract.
5-Trigeminocerebellar fibers: These ascend via the inferior cerebellar peduncles and transmit proprioceptive information from the face to the cerebellum.
explain the cerebellum Efferent pathways
- Efferent tracts originate from the four deep cerebellar nuclei and travel mainly via the superior cerebellar peduncle. The tracts of the fastigial nucleus travel via the inferior cerebellar peduncle.
-and they are 5:
1-Cerebellovestibular tract: This is an output from the cerebellum to the extensor muscles of the axial muscles which coordinate muscle tone adjustment.
2-Cerebelloreticular tract: This tract sends information to the motor circuits of the brain stems.
3-Corticonuclear tract: This connects the cerebral cortex to the brainstem and is functions for the motor function of the oculomotor nerve.
4-Cerebellothalamic tract: This arises from the superior cerebellar peduncle, arises from the cerebellar nuclei and decussates to terminate in the ventral anterior nucleus of the thalamus.
5-Cerebellorubral tract: This sends information from the cerebellum to motor systems of the brainstem.
explain the symptoms of cerebellar damage
-Damage to the cerebellum can lead to:
1) loss of coordination of motor movement (asynergia),
2) the inability to judge distance and when to stop (dysmetria),
3) the inability to perform rapid alternating movements (adiadochokinesia),
4) movement tremors (intention tremor),
5) staggering, wide based walking (ataxic gait),
6) tendency toward falling,
7) weak muscles (hypotonia),
8) slurred speech (ataxic dysarthria),
9) abnormal eye movements (nystagmus).
————- medical terms :
* Gait ataxia—wide-based, reeling. May be more apparent when turning or stopping suddenly. When mild, only tandem gait may be impaired.
* Dysmetria—an inability to perform acute finger-to-nose movements accurately with past pointing or a similar inability on heel/shin testing.
* Dysdiadokinesia—inability to perform rapid alternating movements.
* Tremor—intention or ‘hunting’ tremor (kinetic). Postural (static) tremors may also occur.
* Loss of rhythm—rapid tapping on the back of the hand or tapping the heel on the opposite knee.
* Hypotonia.
* Dysarthria—with slurred speech and a scanning dysarthria as words are broken up into syllables; impaired modulation of volume.
* Eye movements—broken up pursuit movements; overshooting or undershooting targets on saccadic eye movements (saccadic dysmetria). Macrosaccadic square-wave jerks in primary position (sudden short-duration movements laterally with rapid correction).
* Nystagmus—coarse nystagmus with the fast phase in the direction of the lesion; multidirectional nystagmus.
* Hyporeflexia.
explain the THE EXTRAPYRAMIDAL SYSTEM , DF , consist of , function, classification of syndromes , two main syndromes
-DF :It includes all fibers that can influence the MEP and do not pass in the pyramidal tract.
-Consist of :
2-the basal ganglia: n. caudatus, n.lenticularis (putamen, globus palidus)
2-the nuclei of brain stem (black substance, red nucleus, vestibular nuclei, reticular nuclei, nucleus of Darkshevych, Lues’ body, lower olives)
3-spinal cord: γ-motor neurons and α-small motor neurons, which are located in anterior horns of the spinal cord
-function :
1-The initiation and planning of movements
2-Adjusting speed and magnitude of movement
3-Automatically implementation of learned motor programs (walking, cycling, etc.)
4-Implementation of consecutive or simultaneous movements
5-Adjustment of muscle tone
6-Truncal stability
-Classification of syndromes: Movement disorders are classified according to dominant abnormal or involuntary movements
1-hypokinetic (reduced movement) (lesion of pallidum)
-Ex:Parkinson’s syndrome
2-hyperkinetic (increased movement) (lesion of striatum)
-Ex:
Chorea
Athetosis
Choreoathetosis
Ballism and hemiballism
Myoclonus
Torsion spasm
Tics
Facial cramp
Tremor
explain Parkinson syndrome , DF , Etiology
-DF: It is a condition in which there are Static tremors (regular) associated with:
Bradvkinesia & Rigidity (hypertonia) of the muscles of the body
-1) STATIC TREMORS (disturbance in REGULATION ofthe voluntary motor activity):
- Regular: Parkinsonism.
- Irregular: Chorea, athetosis, dystonia
-2) BRAYKINESIA (disturbance in REGULATION ofthe emotional & associated mov):
- Mask face (Inunobile face with infrequent blinking.. staring look).
- Monotonus speech.
- Loss of swinging of the arms during walking.
-3) Rigidity _(Hypertonia) (disturbance in inhibition of the muscle tone).
–Etiology : Deficiency of Dopamine in the Basal Ganglia
- Types :
I. Idiopathic:
- Age:
- Sex:
(paralysis agitans = unknown cause)
Above 50 years.
Both sexes are equally affected.
II. Secondary:
1. INFLAMMATORY: ENCEPHALITIS.
2. VASCULAR: CEREBRAL ATHEROSCLEROSIS.
3. Toxic: Major tranquilizers (Phenothiazines).
4. Traumatic: Repeated trauma to the head as in boxers.
5. Tumours: of the basal ganglia.
explain DYSTONIA and its types
—-Characterized by involuntary, continuous, twisting, rotating muscle contraction
-Develops as a result of simultaneous contractions of agonist and antagonist muscles
-Recurrent
-Results with temporary or permanent abnormal postures
-Disappears during sleep
-Dystonic contractions temporarily loss with touch
—Type of Dystonias :
1-Hemifasyal Spasm Blepharospasm
- Only on half of the face
- May be continuous or intermittent
- Semi-rhythmic contractions
2-Blepharospasm
- Increasing of eye blink frequency functional blindness
3-Oromandibulolingual Dystonia
- Dystonia around the mouth-jaw-tongue
4-Laryngeal Dystonia (pasmodic Dysphonia)
- Difficulty of voicing and speech
5-Cervical Dystonia (spasmodic torticollis)
6-“Task Specific” dystonia
- Occurs only during selective motor functions
- The most common is “writer’s cramp”
explain CHOREA and BALLISM and the differences
-CHOREA and BALLISM
- Arrhythmic, rapid, saltatory or smooth, simple or complex movements
1-Chorea
- Amplitude is smaller
- Usually seen in distal of extremity
2-Ballism
- Amplitude is greater
- Usually seen in proximal of extremity
explain the TREMOR
Tremor
- is involuntary, rhythmic oscillations
- occur as a result of synchronous contraction of the reciprocal muscles
-types :
1. Kinetic tremor
- Intensiyenel tremor (cerebellum)
2. Postural Tremor
3. Resting tremor
explain TIC DISORDERS , df and classification and types
Df :
May suppress as a voluntary for a short time
Unbearable desire to motion from the inside
Involuntary movement (motor tics) or sound (vocal tics)
Short
Non-rhythmic
Stereotypic
As appears aimless
Sudden
-Classifications :
1-simple ( motor , vocal )
- Motor Ex : mouth opening , shoulder shaking
-vocal Ex : primitive sounds throat clearing
2-Complex ( motor , vocal )
- Motor Ex : touching, tapping sniffing
-vocal Ex : singing whistle
